Marvels of Pond-Life. 17 



althougli energetic and comical, afford no certain indi- 

 cations of either purpose or will. What are they ? 

 animals or vegetables? or something betwixt and 

 between ? 



The first impression of any casual observer would be 

 to declare in favour of their animality ; but before this 

 can be settled, comes the question, what is an animal, 

 and how does it differ from a vegetable ? and upon this 

 the learned do by no means agree. One writer con- 

 siders the presence of sta7'ch in any object a proof that 

 it belongs to the dominions of Flora, while another 

 would decide the issue by ascertaining whether it evolves 

 oxygen and absorbs carbon, as most plants do, or whether 

 it evolves carbon and absorbs oxygen, as decided SLuimsils 

 do. Dr. Carpenter asserts that the distinction between 

 Protophyta and Protozoa (first or simplest plants and 

 animals), "lies in the nature of their food, and the 

 method of its introduction, for whilst the Protophyte 

 obtains the materials of its nutrition from the air and 

 moisture that surround it, and possesses the power of 

 detaching oxygen, hydrogen, carbon, and nitrogen from 

 their previous binary combinations, and of uniting them 

 into ternary and quaternary organic compounds (chlo- 

 rophyll, starch, albumen, &c.), the simplest Protozoa, 

 in common with the highest members of the animal 

 kingdom, seems utterly destitute of any such power, 

 makes, so to speak, a stomach for itself in the substance 

 of its body, into which it injects the solid particles that 

 constitute its food, and within which it subjects them 

 to a regular process of digestion.'^ 



Unfortunately it is very difficult to apply this simple 



2 



